Bulk material shipping containers often contain products that are viscous or sticky, thus the products don't flow easily or they adhere to the plastic bag when being dispensed. The result is more residual product left in the plastic bag which becomes expensive waste and a disposal issue for the users. To address this problem, one general prior art solution has been specially designed bags which help in getting the product dispensed.
The prior art has attempted several approaches to overcome this problem. For example, one design approach forces the product to the center of the plastic bag where it can be dispensed out of the top of the plastic bag. Another design approach forces the product to the outlet valve on the bottom of the front panel of the box where it is typically pumped out of the container. These two design approaches incur high cost and complexity and the bag that is used is a three ply bag that has a series of welds between the outer and middle ply that allow air to be inserted between the outer and middle ply in a way so as to force the product inside of the bag to the outlet point.
Another prior art approach was to take a standard form fit bag made with two plies plastic film and then a separate pillow bag is welded it to the form fit bag outside the containment areas. In this approach the pillow is welded to the trim areas of the form fit bag. When air is inflated into this separate pillow bag, it forces the product inside the form fit bag towards the outlet valve. These bags are expensive to make as there are two bags to be made and an off-line process to weld the two plastic bags together. The aforementioned prior art bags' performances are comparable to one another, but not significantly better or worse.
Therefore, there is need for a simple, inexpensive, and effective design to completely evacuate the flowable materials from the bag-in-box.